* Myself a Mandarin, required reading for anyone bound for Hong Kong.

* The phrase ‘ten thousand li’ is widely used in China to describe an entity – most notably the Great Wall – that is known for its extreme length. The phrase is not meant to be taken literally – just as well considering the li's notorious flexibility as a unit of measure: an uphill li being longer than a downhill li, a Shanghai li being shorter than a Chengdu li. But the Yangtze benefits from a happy arithmetical accident: the early western railway builders in China fixed a firm definition onto the unit, making one li equivalent to precisely 25/58ths of an English mile. Since the Yangtze measures 3964 miles from source to sea, Wang Hui might consider his fancy vindicated: his ten-thousand-li river is 9200 li from end to end – near enough.

* Yellow, the quintessential Chinese Imperial colour, was only allowed to be worn by the Emperor and Princes of the Blood Royal.

* There had been all kinds of problems. The ships owned by the company had all been built in East Germany for the Volga trade and drew three feet more than was permissible in this unusually low-water autumn. So a journey that normally took three days took five, and involved two boats and a day-long bus journey. The following day the same bus, performing the same portage, crashed, killing three passengers.